Rotary variable condenser.



l Patented July 23, 1912.

ill f' l H.GERNSBACK.

` ROTARY VARIABLE ooNDENsER.

APPLIOATIQN IILED MAR. 1, 1912;

.4: A l M,

| f7 l -nvucntozl MI winaoggp UNITED sTATEs PATENT oEEicE.

HUGO GERNSBACK, 0F NEW YORK, N. Y.

ROTARY VARIABLE CONDENSER.

T0 all whom t may concern:

Be it known that I, HUGO GERN'SBACK, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Rotary Variable Condensers, of which the following is a specification.

The present invention relates to a variable condenser which is more especially designed for use in connection with wireless telegraphy and telephony, and which is also adapted for use in the'other electrical arts in which such condensers lare used.

The object of the invention is to provide a variable condenser which has a rotary adjusting movement, which is very compact in its construction, which can be easily and quickly manipulated, and which is peculiarly designed so as to render short circuiting practically impossible.

The present variable condensers which use intermcshing plates with air dielectric are very bulky owing to the fact that the plates can never approach each other very closely, and are also unsatisfactory owing yto the fact that they are liable tol get out of repair and much leakage is caused. With the present construction these objections are avoided, since no plates with sharp edges are used, and the parts are simple and work with little friction or wear, thereby rendering the device very durable and long lived.

`Vith these and other objects in view, the invention consists in certain novel combinations and .arrangementsof the parts as will more fully appear as the description proceeds, the novel features thereof being pointed out in the appended claims.

For a full understanding of the invention, reference is to be had to the following description and accompanying drawing, in which Figure 1 is an end View of a rotary variable condenser constructed in accordlance with the invention. Fig. 2 is a transverse vert-ical sectional view through the same, and Fig. 3 is a longitudinal vertical sectional view through the condenser.

Corresponding and like parts are referred 'to in the following description and indicated in all the views of the drawings by the` same reference characters.

Various mechanical constructions can be employed for carrymg out the invention,

the essential feature of the invention resid-y ing in the provision of a rotary drum upon which sheets of conducting and dielectric material are adapted to be wound and unwound for the purpose of varying the effective capacity of the condenser.

One embodiment of the invention is illustra-ted by the accompanying drawings, in which the mechanism is housed Within a casing 1. A drum 2 and pair of rollers 3 which have a parallel and spaced relation to each other are suitably journaled within the casing, one of the trunnions 4 of the drumr1 2 projecting through 'one end of the casing and being provided with a suitable knob or handle 15. This handle would preferably be formed of some insulating material such as hard rubber, and constitutes a means for turning the drum 2. One `end of the drum 2 is provided with a gear wheel 5 which meshes with corresponding gear wheels 6 upon the rollers 3. These gear wheels may be formed of ber or other suitable material and serve Vto simultaneously turn the rollers 3 when the drum 2 is rotated in either direction. A sheet 7 of conducting material, and also a sheet S of dielectric material is provided for each of the rollers. These sheets of dielectric and conductingnaterial are fitted against each other so as to have a superposed relation, one end of each of the sheets being secured to the drum 2 in some suitable manner, while the opposite end of each of the heetsis secured to the corresponding roller 3. These be secured to the rollers and drum in any suitable or -approved manner, the present instance rollers are shown as formed in longitudinal sections which are' held together by means of the fastening members or bolts 9, the ends of the sheets 7 and 8 being inserted between the longitudinal sections of the `druln and rollers and clamped securely in position by means of the bolts 9. The sheets 7 and 8 sheets may although in Y. both the drum and the extend from the bottom of the drum 2 to the top of one of the .rollers 3 and from the top of the drum 2 posite roller 3, and these sheet-s are so -arranged as to be wound upon the drum 2 and unwound from the rollers 3 when the drum is turned in one direction and unwound from the drum 2 and wound upon the respective rollers 3 when the said drum is turned in the opposite direction. It will further be observed that the sheets of conducting and dielectric material7 and 8 are so to 'the bottom of the oparranged upon the drum and rollers that a layer of dielectric material is always interposed between successive layers of conduct ing material upon both the Idrum and the rollers, thereby preventing the sheets of conducting material from being brought into contact with each other or with successive turns of the same sheet as they are wound upon the drum 2. Any suitable means may be providedvfor making contact with the sheets 7 of conducting material, and in the present instance a pair of spring brushes or contact members 10 are provided. These spring brushes 10 are secured to opposite sides of the casing l and have a yielding engagement with the respective sheets 7 of conducting material upon the rollers 3. Thesebrushes .10 are connected by suitable conductors 11 to binding posts l2 at the top of the casing l.

lVith the foregoing construction, it will be obvious that by grasping the knob or finger piece and turning the drum 2 the sheets 7 and 8 of conducting and dielectric material can be wound upon or unwound from the drum 2, the effective capacity of the condenser being increased asl the -said sheets are wound upon the drum 2 and decreased asthe said sheets are unwound from the drum 2. A fine and accurate adjustment can,be readily obtained and the device will hold its adjustment after the handle has been released without the necessity of tightening a set screw or othermember. Furthermore, no amount of shaking or vibration can affect the adjustment, and short circuiting of the condenser is impossible under any ordinary circumstances. For convenience in adjusting the condenser, a pointer 13 may be applied to the trunnion 4 of the drum 2 and a scale 14 mounted upon the I end of the casing 1 for coperation with the `.pointe1.. This scale 14 may besuitably graduated and enables the operatorto readily adjust the condenser as maybe desired.

While I have illustrated two rolls as employed in connection with the drum 2, it will be obvious Nthat any desired number of rolls could be employed without departing in any manner from the spirit of the invention. It would also be possible to entirely eliminate the rolls and use only the drum, in which instance the conducting and dielectric sheets would be arranged to be rolled uponand unrolled from the drum in somewhat the same manner as that in which a curtain shade is wound upon and unwound from a shade roller. By using suitable dielectric material in forming the insulating sheets, the condenser could be easily built for high tension currents, although for ordinary purposes varnished or oiled silk could lbe advantageously used for the dielectric sheets, and metallic foil of any suitable 65 material such as copper, tin, aluminium,

nickel, or the like for the conducting sheets. llt will also beobvious that the condenser could be sunk in oil, or any other high grade insulating fluid in order to keep the condenser from breaking down when used with high tension currents.

Bearings 1G and 17 are shown as arranged in opposite ends of the casing 1`for the trunnions of the drum and rolls, and the drum 2 is shown as provided at one-end thereof with a radially projecting pin 18 adapted to engage a stop 19 to limit the turning of the drum. This stop is so arranged as to prevent tearing of the flexible sheets when the drum has been turned in either direction to either entirely Wind the flexible sheets upon the drum or unwind them therefrom. Any suitable form of stop might be employed for this purpose, since it is merely necessary to make some mechanical provision for limiting the rotation of the drum in order to prevent tearing or injury of the flexible sheets.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent, is

1. A rotary variable condenser including a drum, flexible sheets of dielectric and conducting material, and means for winding the said sheets upon the drum and unwinding them therefrom, the dielectric material being alwaysjinterposed between successive layers of the conducting material upon the drum.

2.'A rotary variable condenser including a drum, a plurality of flexible sheets of conducting material, a sheet of dielectric material for each sheet of conducting material, the said sheets of conducting and dielectric material being secured to the drum, and means for turning the drum to simultaneously wind the said sheets thereon or unwind the sheets therefrom, the dielectric material being always interposed between successive layers of the conducting material, upon the drum.

3. A rotary variable condenser including a drum, flexible sheets of dielectric and conducting material, means for winding the I said sheets upon the drum and unwinding them therefrom, and indicating means for showing the amount of the sheets wound upon the drum. y

4f. A rotary variable condenser including a drum, flexible sheets of dielectric and conducting material secured to the drum, means for winding the said sheets upon the drum and unwinding them therefrom, the dielectric material being always interposed between successive layers of the conducting material upon the drum, and sliding contact members engaging the sheets of conducting material.

5. A rotary variable condenser includingA a drum, a plurality of flexible sheets of conducting material, a sheet of flexible dielectric material for each of i the conducting sheets, the said sheets being secured to '.the drum, means for turning the drum to simultaneouslywind the sheets upon the drum or unwind them therefrom, sliding contacts engaging the sheets of conducting material, and lndicating means for showing the amount of the sheets wound upon .the drum. 6. A rotary variable condenser including a drum, a roll, sheets of dielectric and insulating material having opposite ends thereof secured'to the drum and the roll, means for simultaneously turning the drum and roll to wind the sheets 'from one of the members upon the opposite member, and contacts adjustably engaging the sheets of' conducting material.

7 A rotary variable condenser including a drum, a plurality of rolls, a sheet of di- I electric material and a sheet of conducting material for eachl of the rolls, one end' of each of the sheets being connected to the drum while the opposite end thereof is connected to the respective roll, contact members engaging the conduct-ing sheets, and means for winding the sheets of dielectric and conducting material upon the drum from the several rolls or from the drum to the several rolls. t

8. A rotary variable condenser including a drum, a plurality of rolls, gearing between the drum and the various rolls, a sheet of conducting material'and a sheet of dielectric material for each of the rolls, one end of eachof the sheets being secured to the drum while the opposite end is secured tothe corresponding roll, contact members engaging '1 the conducting sheets, and means for rotating the drum and rolls to simultaneously wind the various sheets from therolls upon the drum or from the drum. upon the rolls.

9. A rotary variable condenser including a drum, a plurality of rolls, gearing between the drum and rolls, a sheet of dielectric naterial and a sheet of conducting material for each of the rolls, one end of each of. the sheets being secured to the drum, while the opposite end thereof is secured to the respective roll, contact members engaging the conducting sheets, a finger piece "for simultaneously turning the drum and rolls .to

wind the various sheets from the rolls upon the drum or from the drum upon the rolls, a pointer movable with the finger piece, and a scale coperating with the pointer to indi-4 the drum.

10. A rotary variable condenser including a drum, a plurality of rolls, both the drum and rollsbeing Jformed in longitudinal sections, gearing between the drum and rolls,

Vcate the amount of the sheets wound upon (sol sheets. of dielectric and conducting material f for each of the rolls, one end of eachbf the sheets being clamped between the sections of the drum while the opposite end of each of the sheets is clamped between the sections of the corresponding roll, contact members engaging the conducting sheets, and means for turning the drum to wind the sheets from the rolls upon the drum or from the drum upon the rolls.

In testimony whereo'I aiiix my signature 1 in presence of two witnesses, y

HUGO GERNSYIBACK. Witnesses:

S. GERNSBACK, E. R. WEADoN. 

